function preamble=qd()
b=[1,1,-1,-1,1,1,-1,1,-1,1,1,1,1,1,1,-1,-1,1,1,-1,1,-1,1,1,1,1,1,-1,-1,1,1,-1,1,-1,1,-1,-1,-1,-1,-1,1,1,-1,-1,1,-1,1,-1,1,1,1,1];
s=sqrt(13/6)*[0,0,1+1i,0,0,0,-1-1i,0,0,0,1i+1i,0,0,0,-1-1i,0,0,0,-1-1i,0,0,0,1+1i,0,0,0,0,0,0,-1-1i,0,0,0,-1-1i,0,0,0,1+1i,0,0,0,1+1i,0,0,01+1i,0,0,0,1+1i,0,0,0];
time_syms=IFFT64(s);
g=1;
for w=1:16
x(g)=time_syms(w);
g=g+1;
end
short=[x,x,x,x,x,x,x,x,x,x];
%short(1)=short(1)*0.5;
short(160)=short(160)*0.5;
time_syms=IFFT64(b);
g=1;
for w=33:64
y(g)=time_syms(w);
g=g+1;
end
long=[y,time_syms,time_syms];
%long(1)=long(1)*0.5;
long(160)=long(160)*0.5;
%short(160)=short(160)+long(1);
%long(1)=[];
preamble=[short,long];